Charge 7 said:
Funny, but Stalin wouldn't have agreed with you. He demanded that the western front be opened up and as Italy was essentially a stalemate the Normandy invasion was the only way that was going to happen. Obviously, he felt Normandy was decisive.
Could the Russians have won on their own? Maybe, maybe not. What is certain is that the huge amount of equipment sent to them by America with Lend Lease and by the British as well they wouldn't have been very likely to have held on. True, they had vast reserves of manpower, but manpower without equipment is just so many targets as the Russians well proved when they sent men into battle without weapons and expected them to get a rifle from the dead.
Frankly, I'm sick of all this "they did it all" deal so far as the Russians go. They didn't do it all. The Allies did it together. Many battles were decisive. Midway was decisive, El Alamein was decisive, Guadalcanal was decisive and oh so many others.
In all actuality the two most decisive battles aren't even in your list. The battle of Poland was the most decisive for Germany because it ensured that the Allies would eventually oppose them and put an end to appeasement. Germany never had a chance to win against the combined might of the Allies. And yes, Russia did take half of Poland in that bargin, but that only ensured that Poland would no longer be a buffer between them and Germany and Hitler's dream of leibensraum would go on so that they too would oppose Hitler. Likewise, for Japan Pearl Harbor was the most decisive as it ensured that their dream of expansion in the Pacific would be put to an end as well.
It's true that Stalin demanded that the Western Allies open up a second front (or in this case a third one). That's different though from stating that said second front was actually decisive, which is the topic of this thread after all.
After Kursk, where the Wehrmacht lost the strategic initiative, the Red Army was more than capable of beating the Germans alone, but you're right - they did need western help. In fact, western help IMO was absolutely
critical to Soviet success. Not because of D-Day or El-Alamein, important though they were. Because of Lend-Lease, which in my opinion was CRITICAL to the survival of the Soviet Union in WW2.
Without Lend-Lease the Soviet Railroad system would have collapsed, meaning it would have been very difficult for the Soviet Union to supply, mobilise and deploy her armies. One of the biggest impacts is that most of the Soviet motorised rifle divisions would have had to slog it on foot. Furthermore, the Red Army would not have been capable of moving enough supplies and equipment to conduct large scale operations such as the defense of Kursk or the Battle of Bagration. They would be limited to conducting rolling waves of localised attacks that would have easily been outflanked and out maneuvered by the more mobile German divisions.
Taking that into consideration and also the fact that Lend-Lease delivered large supplies of extremely useful supplies such as tyres and machine tools, the Red Army would have been very hard pressed to wage war on anything like equal terms with the Wehrmacht and it's my opinion that they would have eventually collapsed. Even with Lend-Lease the Soviet-German casualty ratio was around 5-1 for the first 2 years of Operation Barbarossa; it would have been much worse without.
http://orbat.com/site/sturmvogel/SovLendLease.html
I wouldn't say that the Battle of Poland was decisive, because although it did ensure that France and Great Britain (NOT the US at this stage) would oppose Germany, by itself it did nothing to turn the tide of events. Although France and the UK had declared war, they actually did very little whilst Germany happily conquered Poland. Therefore, the expected 2-front war did not materialize at that time. By 1940 France was humbled and the UK isolated. At that point there was little in the way of actual large-scale combat until 1941. You could argue then that Germany, at that point, had already won the war.
I would agree that Pearl Harbor was
utterly decisive because it ensured that the US would enter WW2 - until that event direct US participation in WW2 was far from certain. I think we need to separate the European and Pacific Theatres because for all extents and purposes they were separate campaigns.
One final thing - you state that Germany would never have been able to defeat the combined might of the allies. I don't agree with that statement at all. That's why the Nazis were so dangerous - they really could have won. Germany had every chance and one could argue that Germany as much lost the war as the Allies won. Germany made some huge mistakes in WW2, none bigger than Operation Barbarossa. Not because they decided to launch it, more because they did so with such unbelievable overconfidence. That's why IMO US involvement, Pearl Harbor or not, would probably have occurred at some point. With the German technological superiority in chemistry and rocketry, the US could not longer play the isolationist card.